Technologies for high resolution and wide swath spectrometer

Abstract

Technologies for a high resolution and wide swath spectrometer are disclosed. In the illustrative embodiment, an inverted image slicer converts a linear field of view into a grid shape, allowing for an interferometer of a Fourier transform spectrometer to operate on a narrow range of field of views, improving the average spectral resolution of the spectrometer.

The invention claimed is: 
     
       1. A spectrometer comprising:
 an inverted image slicer configured to accept input light to the spectrometer; 
 an adjustable interferometer configured to accept light from the inverted image slicer; 
 a sensor configured to sense light from the interferometer; 
 wherein the inverted image slicer causes a linear field of view of the spectrometer to be imaged as a two-dimensional grid on the sensor. 
 
     
     
       2. The spectrometer of  claim 1 , wherein the sensor is configured to sense a range of wavelengths, wherein the range of wavelengths includes 6.2 micrometers. 
     
     
       3. The spectrometer of  claim 2 , wherein the sensor comprises a two-dimensional array of pixels, wherein data from each pixel of the two-dimensional array of pixels can be used to determine a spectrum of light imaged at that pixel with a resolution better than 2 cm −1 . 
     
     
       4. The spectrometer of  claim 1 , wherein the inverted image slicer converts a field of view with at least one dimension extending across at least 100 milliradians to a field of view with each dimension extending across less than 90 milliradians. 
     
     
       5. The spectrometer of  claim 4 , wherein the sensor comprises a two-dimensional array of pixels, wherein each pixel images a field of view between 0.005 and 30 milliradians. 
     
     
       6. The spectrometer of  claim 1 , wherein the inverted image slicer comprises:
 a first lens to focus input light onto a first plurality of mirrors; 
 the first plurality of mirrors, wherein each of the first plurality of mirrors is tilted at an angle different from each other of the first plurality of mirrors, wherein each of the first plurality of mirrors is configured to direct light from the first lens to a corresponding mirror of a second plurality of mirrors; 
 the second plurality of mirrors, wherein each of the second plurality of mirrors is configured to direct light from the corresponding mirror of the first plurality of mirrors to a corresponding mirror of a third plurality of mirrors; 
 the third plurality of mirrors, wherein each of the third plurality of mirrors is tilted at an angle different from each other of the third plurality of mirrors, wherein each of the third plurality of mirrors is configured to direct light from a corresponding mirror of the second plurality of mirrors to a second lens; and 
 the second lens. 
 
     
     
       7. The spectrometer of  claim 6 , wherein each of the second plurality of mirrors is configured to image a surface of the corresponding mirror of the first plurality of mirrors on a surface of the corresponding mirror of the second plurality of mirrors. 
     
     
       8. The spectrometer of  claim 1 , wherein the interferometer comprises a beam splitter, a first mirror, and a second mirror, wherein each of the first mirror and the second mirror is a corner-cube mirror. 
     
     
       9. The spectrometer of  claim 1 , wherein the interferometer is in a Michelson configuration. 
     
     
       10. A satellite comprising the spectrometer of  claim 1 . 
     
     
       11. A method of using a spectrometer, the method comprising:
 gathering light into an inverted image slicer, the inverted image slicer configured to accept input light to the spectrometer; 
 transmitting light from the inverted image slicer to an adjustable interferometer; and 
 detecting light from the adjustable interferometer at a sensor, 
 wherein the inverted image slicer causes a linear field of view of the spectrometer to be imaged as a two-dimensional grid on the sensor. 
 
     
     
       12. The method of  claim 11 , further comprising analyzing data from the sensor to determine a spectrum of the gathered light. 
     
     
       13. The method of  claim 12 , further comprising predicting the weather based on the spectrum of the gathered light. 
     
     
       14. The method of  claim 11 , wherein the sensor is configured to sense a range of wavelengths, wherein the range of wavelengths includes 6.2 micrometers. 
     
     
       15. The method of  claim 14 , wherein the sensor comprises a two-dimensional array of pixels, wherein data from each pixel of the two-dimensional array of pixels can be used to determine a spectrum of light imaged at that pixel with a resolution better than 2 cm −1 . 
     
     
       16. The method of  claim 11 , wherein the inverted image slicer converts a field of view with at least one dimension extending across at least 100 milliradians to a field of view with each dimension extending across less than 90 milliradians. 
     
     
       17. The method of  claim 11 , wherein the inverted image slicer comprises:
 a first lens to focus input light onto a first plurality of mirrors; 
 the first plurality of mirrors, wherein each of the first plurality of mirrors is tilted at an angle different from each other of the first plurality of mirrors, wherein each of the first plurality of mirrors is configured to direct light from the first lens to a corresponding mirror of a second plurality of mirrors; 
 the second plurality of mirrors, wherein each of the second plurality of mirrors is configured to direct light from the corresponding mirror of the first plurality of mirrors to a corresponding mirror of a third plurality of mirrors; 
 the third plurality of mirrors, wherein each of the third plurality of mirrors is tilted at an angle different from each other of the third plurality of mirrors, wherein each of the third plurality of mirrors is configured to direct light from a corresponding mirror of the second plurality of mirrors to a second lens; and 
 the second lens. 
 
     
     
       18. The method of  claim 17 , wherein each of the second plurality of mirrors is configured to image a surface of the corresponding mirror of the first plurality of mirrors on a surface of the corresponding mirror of the second plurality of mirrors. 
     
     
       19. The method of  claim 11 , wherein the interferometer comprises a beam splitter, a first mirror, and a second mirror, wherein each of the first mirror and the second mirror is a corner-cube mirror. 
     
     
       20. The method of  claim 11 , wherein the spectrometer is on a satellite orbiting Earth.